1. Field of the Invention
Methods and apparatuses consistent with the present invention relate to compressing an image signal, and more particularly, to compressing an image signal, so as to improve a compression rate by modifying a transform matrix.
2. Description of the Related Art
A discrete cosine transform (DCT) is a well-known technology that is used in video, image, or audio compression. In recent years, several attempts were made to develop a more efficient coding method, and due to this, in audio coding, parametric coding has shown better results than DCT. Regarding two-dimensional (2D) data, Karhunen Loeve transform (KLT) coefficients have the minimum bit interval, but the amount of overhead information remarkably increases.